The present invention relates to a space frame which has a plurality of joint elements provided with connecting members. More particularly, it relates to such a space frame in which the above joint elements are formed as releasably connectable bodies having approximtely or polyhedral shape and connected with one another tubular and/or bar-shaped connecting pieces which are releasable connectable with the connecting members of the bodies, for example by means of screw connection.
Space frames of the above mentioned general type are disclosed, for example, in the DE-OS No. 2,917,422. The joint elements are composed in this space frame of hollow two-part metal balls with radial through openings. These metal balls have spatial access openings which are closed by caps. The caps are mounted on the balls by means of holding-down springs. The manufacturing and assembling of such joint elements is expensive since many manufacturing steps are required to obtain a finished ball from a workpiece. Another disadvantage of the known joint elements is that the region of the metal balls which is closed by the caps cannot be used for connecting with the connecting pieces and the force distribution on the the joint element is not uniform. It is possible to reduce the effect of this unfavorable force distribution for example by making greater the wall thickness of the hollow ball. However, this leads to an increased material consumption and further increase in costs of the joint elements.
Another space frame is disclosed in European patent application No. 0.081,608. The caps of the metal balls are provided with openings for the tubular bars. The connection of the both ball parts is performed by means of a screw which undesirably affects the mounting of the space frame because of the openings formed in the caps.